1. Field of the Invention
This invention relates to refuse management systems, and more particularly to management systems for refuse compactors.
2. Description of the Related Art
Many large retail establishments own or lease refuse compactor systems. These systems usually include a trash compactor unit secured to a container. The container is separable from the compactor unit and can be loaded for transportation by truck to a landfill. Although containers vary in size, a container in common use can typically hold 40 cubic yards of compacted material. When the container is full, the retail establishment typically schedules a refuse hauling service to remove and empty the container. The hauling service sometimes exchanges an empty container for the full container at the retail establishment site to avoid interruption of the establishment's activities. Typically, an indicator light is located on the compactor to inform a user when the container is full. The light is illuminated in response to a pressure that meets or exceeds the preset maximum hydraulic pressure, the assumption being that the compactor cannot crush any further refuse into the container. However, the light can illuminate falsely when unusually hard refuse, such as wooden pallets, are deposited in the container. In addition, retail clerks responsible for loading the container and operating the compactor often fail to pay attention to the light when illuminated. Consequently, refuse backs up into storage areas of the retail establishment otherwise reserved for product shipments until a hauler can be scheduled to empty the container. This problem is augmented on weekends when many refuse hauling companies are closed. As a result, many establishments have the container emptied on a regular basis, whether or not the container is full. However, landfills often charge a standard rate for the size of the container, regardless of the actual amount of refuse disposed. Thus, the retail establishment is subject to additional unnecessary charges from both the hauling company and the landfill.
A refuse management system currently in use has attempted to overcome these problems by the provision of a programmable logic controller (PLC) installed at the compactor site. The PLC gathers, sorts, and stores information about the compactor's operation. A computer at a remote location can access the information stored in the PLC when prompted by a computer operator. The information can then be downloaded and printed into a report. The report is analyzed by a person knowledgeable in statistical analysis and the particular parameters of the compactor in review. The person must then determine when the container will be full and make arrangements with the hauling company to pick up the container. However, the information gathered by the PLC at the compactor site is not available to the end user. The end user does not know what decisions have been made and therefore cannot accurately schedule for compactor down time.
Another problem associated with the current system occurs frequently when the refuse container is removed for dumping. A proximity sensor normally senses the container's presence. When the container is pulled, the proximity sensor is actuated and some of the values stored in the PLC representative of the compactor system conditions, such as average pressure, amount of usage since last pull, etc., are reset. However, the compactor and its associated PLC are sometimes disconnected from their electrical source when the container is separated from the compactor, and reconnected after the empty container and compactor are rejoined. The proximity sensor in this circumstance does not generate a signal to reset the current values. As a result, the currently stored values are inaccurate and can be interpreted erroneously.